Field
The present invention relates to a fuel cell system and a fuel cell system control method.
Related Art
With a fuel cell system equipped with a polymer electrolyte fuel cell (hereafter also simply referred to as a “fuel cell”), there are cases of using a pump equipped with a rotating body that is also called a rotor to supply reaction gas to the fuel cell. As a hydrogen pump for circulating hydrogen exhausted from an outlet of the anode of the fuel cell to the inlet of the anode of the fuel cell, typically, a roots type pump is used (e.g. JP 2009-138713, JP2007-024015 or the like).
The moisture generated by the power generation reaction of the fuel cell flows into the hydrogen pump which is used for circulation of hydrogen together with exhaust gas. In a low-temperature environment, such as sub-zero, there are cases that the rotating body and the case are adhered by the freeze of the moisture that remains within the hydrogen pump entering in the gap between the rotating body of the hydrogen pump and the wall surface of the case, which is the casing for housing the rotating body. Because of that, there is the problem that starting of the hydrogen pump becomes difficult when operation of the fuel cell is started. This kind of problem is not limited to roots type hydrogen pumps used for the circulation of hydrogen in the fuel cell systems, but is a problem that is common to pumps equipped with a rotating body used for the fuel cell systems.